People are becoming increasingly concerned about safety issues including personal safety, burglary and traffic accidents. To reduce the damage caused by these kinds of public safety issues, a video based monitoring systems are popularly used to instantaneously monitor and review abnormal events.
The monitoring system can save both audio and visual data and therefore acts as a deterrent against those who would cause bodily harm, burgle a home are drive a vehicle dangerously thereby improving the overall safety of the general public. Therefore, the fact can be easily understood even when each of the interested parties sticks to his own argument. Accordingly, the instantaneous monitoring function and the identification accuracy of the monitoring system are very important. However, most of the conventional monitoring systems use coaxial cables to transmit video signals. Hence, the transmission distance of the conventional monitoring system is limited. Otherwise, the coaxial cables have to be configured through many signal amplifiers to enlarge the transmission distance. Therefore, the cost of the conventional monitoring system is increased. In addition, if the video signals transmitted by the public network, such as Internet, the video quality has to be downgraded to match the transmittable bandwidth in the public network.